This project seeks to document the relationship between alcohol use and medical care utilization by an examination of the multiple data sources within the Kaiser Foundation Health Services Research Center. The Research Center uses, as a medical care laboratory, the Oregon Region of the Kaiser Foundation Health Plan. Data from an open-ended 5 percent sample of the membership of the Health Plan is computerized on an on-going basis, and has been since 1969. These data include all contacts made by members of the sample with the medical care system, the reason for the contact, and the content of the contact. A computer search of these records is used to make the initial identification of persons who have received alcohol related diagnoses. Chart review validates this identification and yields additional data. A next step in the project will be the identification of a matched sample of persons who have not received alcohol related diagnoses in order that the medical care utilization patterns of persons identified as having alcohol related problems can be compared with the utilization patterns of persons without such an identification.